A jaguar in Brazil set a record with a swim of almost two kilometres

Previously, it was believed that such barriers were impassable for large predators.

The animal was first captured by a camera trap on the mainland back in 2020, and was recently recorded on an island 2.48 kilometres from that point. A comparison of the unique pattern of spots confirmed that we are talking about the same jaguar.

Scientists have calculated possible routes. Either the animal swam 2.48 kilometres directly or used an intermediate small island, which required two swims: first 1.06 kilometres, then another 1.27 kilometres. Even the minimum distance was a record: previously, the maximum recorded swimming distance for jaguars was about 200 metres.

This discovery, presented in a bioRxiv preprint, showed: reservoirs are not always absolute barriers for large predators. Rare cases of water crossings are possible under favourable conditions - warm water, low currents and the presence of "stepped" islands.

To assess such crossings, the researchers proposed a new scale of 'water costs': low (up to 300 m), medium (300-1000 m with islands) and high (over 1000 m of open water). This approach could be used in future assessments of hydropower impacts on biodiversity.

The authors emphasise that jaguars, like other large carnivores, need the ability to migrate to maintain the gene pool and rebuild populations. The species has already lost about 50 per cent of its range due to habitat destruction and landscape fragmentation.